Article directory
dmesg
Display Linux system startup information
Additional information
The dmesg command is used to inspect and control the kernel's ring buffer. The kernel will store boot information in the ring buffer. If you don't have time to check the information when booting, you can use dmesg to check it. Boot information is stored in the /var/log/dmesg file.
grammar
dmesg(选项)
Options
- -c: After displaying the information, clear the contents of the ring buffer;
- -s<buffer size>: The default setting is 8196, which is exactly equal to the size of the ring buffer;
- -n: Set the level of recording information.
Example
[root@localhost ~]# dmesg | head
Linux version 2.6.18-348.6.1.el5 ([email protected]) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-54)) #1 SMP Tue May 21 15:34:22 EDT 2013
BIOS-provided physical RAM map:
BIOS-e820: 0000000000010000 - 000000000009f400 (usable)
BIOS-e820: 000000000009f400 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 000000007f590000 (usable)
BIOS-e820: 000000007f590000 - 000000007f5e3000 (ACPI NVS)
BIOS-e820: 000000007f5e3000 - 000000007f5f0000 (ACPI data)
BIOS-e820: 000000007f5f0000 - 000000007f600000 (reserved)
BIOS-e820: 00000000e0000000 - 00000000e8000000 (reserved)
View basic hard drive information
dmesg | grep sda
[ 2.442555] sd 0:0:0:0: [sda] 488281250 512-byte logical blocks: (250 GB/232 GiB)
[ 2.442590] sd 0:0:0:0: [sda] Write Protect is off
[ 2.442592] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 2.442607] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 2.447533] sda: sda1
[ 2.448503] sd 0:0:0:0: [sda] Attached SCSI disk
message
Set write permissions for the current terminal
Additional information
The mesg command is used to set the write permission of the current terminal, that is, whether to allow other users to send messages to this terminal. When mesg is set to y, other users can use the write command to display information directly on your screen.
grammar
mesg(参数)
parameter
- y/n: y means allowing other users to display information directly on your screen, n means prohibiting it.
Example
[root@localhost ~]# mesg y #允许系统用户将信息直接显示在你的屏幕上。
[root@localhost ~]# mesg n #不允许系统用户将信息直接显示在你的屏幕上。
Learn from scratchpython
[Learn python from scratch] 92. Use Python’s requests library to send HTTP requests and process responses
[Learn python from scratch] 91. Use decorators and dictionaries to manage request paths in a simple web application
[Learn python from scratch] 93. Use dictionary management Request path
[Learn python from scratch] 89. Use WSGI to build a simple and efficient Web server
[Learn python from scratch] 88. Detailed explanation of WSGI interface: realize simple and efficient web development
[Learn python from scratch] 87. Manually build an HTTP server in Python Implementation and multi-threaded concurrent processing
[Learn python from scratch] 86. In-depth understanding of the HTTP protocol and its role in browser and server communication
[Learn python from scratch] 85. Application of parallel computing technology in Python process pool
[Learn python from scratch] ] 84. In-depth understanding of threads and processes
[Learn python from scratch] 83. Python multi-process programming and the use of process pools
[Learn python from scratch] 82. Chat program implementation based on multi-threading
[Learn python from scratch] 81. Python more Application of thread communication and queue
[Learn python from scratch] 80. Thread access to global variables and thread safety issues
[Learn python from scratch] 79. Thread access to global variables and thread safety issues
[Learn python from scratch] 78. File download case
[ Learn python from scratch] 77. TCP server programming and precautions
[learn python from scratch] 76. Server and client: key components of network communication
[learn python from scratch] 75. TCP protocol: reliable connection-oriented transmission layer communication protocol
[Learn python from scratch] 74. UDP network program: Detailed explanation of port issues and binding information
[Learn python from scratch] 73. UDP network program - sending data
[Learn python from scratch] 72. In-depth understanding of Socket communication and creation of sockets Method
[Learn python from scratch] 71. Network ports and their functions
[Learn python from scratch] 70. Network communication methods and their applications: from direct communication to routers to connect multiple networks
[Learn python from scratch] 69. Network communication and IP address classification analysis
[Learn python from scratch] 68. Greedy and non-greedy modes in Python regular expressions
[Learn python from scratch] 67. The re module in Python: regular replacement and advanced matching technology
[Learn python from scratch] 66 .In-depth understanding of regular expressions: a powerful tool for pattern matching and text processing
[Learn python from scratch] 65. Detailed explanation of Python regular expression modifiers and their applications
[Learn python from scratch] 64. The re.compile method in Python regular expressions Detailed explanation of usage
[Learn python from scratch] 63. Introduction to the re.Match class and its attributes and methods in regular expressions
[Learn python from scratch] 62. Python regular expressions: a powerful string matching tool
[Learn python from scratch] 61. Detailed explanation and application examples of property attributes in Python
[Learn python from scratch] 60. Exploration generator: a flexible tool for iteration
[Learn python from scratch] 59. Iterator: An efficient tool for optimizing data traversal
[Learn python from scratch] 58. Custom exceptions in Python and methods of raising exceptions
[Learn python from scratch] 57. Use the with keyword in Python to correctly close resources
[Learn python from scratch] 56. The importance and application of exception handling in programming
[Learn python from scratch] 55. Serialization and sum in Python Deserialization, application of JSON and pickle modules
[Learn python from scratch] 54. Writing data in memory
[Learn python from scratch] 53. CSV files and Python’s CSV module
[Learn python from scratch] 52. Reading and writing files - Python file operation guide
[Learn python from scratch] 51. Opening and closing files and their applications in Python
[Learn python from scratch] 49. Object-related built-in functions in Python and their usage
[Learn python from scratch] 48 .Detailed explanation of inheritance and multiple inheritance in Python
[Learn python from scratch] 47. The concept and basic use of inheritance in object-oriented programming
[Learn python from scratch] 46. Analysis of __new__ and __init__ methods and singletons in Python Design Patterns
[Learn python from scratch] 45. Class methods and static methods in Python
[Learn python from scratch] 44. Private properties and methods in object-oriented programming
[Learn python from scratch] 43. Examples in Python object-oriented programming Properties and class attributes
[Learn python from scratch] 42. Built-in properties and methods in Python
[Learn python from scratch] 41. python magic method (2)
[Learn python from scratch] 40. python magic method (1)
[Learn python from scratch] 39. Basic object-oriented syntax and application examples
[Learn python from scratch] 38. How to use and import Python packages
[Learn python from scratch] 37. The use and precautions of Python custom modules
[Learn python from scratch] Learn python] 36. Methods and techniques of using pip for third-party package management in Python
[Learn python from scratch] 35. Python common system modules and their usage
[Learn python from scratch] 34. Detailed explanation of the import and use of Python modules
[ Learn python from scratch] 33. The role of decorators (2)
[Learn python from scratch] 32. The role of decorators (1)
[Learn python from scratch] 31. In-depth understanding of higher-order functions and closures in Python
[From Learn python from scratch】30. In-depth understanding of recursive functions and anonymous functions
【learn python from scratch】29. "Detailed explanation of function parameters" - understand the different uses of Python function parameters
【learn python from scratch】28. Local variables and global variables in Python Variables
[Learn python from scratch] 27. The use of Python functions and nested calls
[Learn python from scratch] 25. Functions: a tool to improve the efficiency of code writing
[Learn python from scratch] 24. String operations and traversal methods in Python
[Learn python from scratch] 23. How to use sets (set) and common operations in Python
[Learn python from scratch] 22. Add, delete, modify, and query dictionary variables in Python
[Learn python from scratch] 21. Python tuples and dictionaries
[Learn python from scratch] 20. Python list operation skills and examples
[Learn python from scratch] 19. Applications of looping through lists and list nesting
[Learn python from scratch] 18. Detailed explanation of the basic operations of Python lists (1)
[From Learning python from scratch】 17. The format method of Python strings (2)
【Learning python from scratch】 16. The format method of Python strings (1)
【Learning python from scratch】 15. In-depth understanding of strings and character set encoding
【From Learning python from scratch】14. Common operations on Python strings (2)
【Learning python from scratch】13. Common operations on Python strings (1)
【Learning python from scratch】12. Python string operations and applications
【Learning python from scratch】 11. Python loop statements and control flow
[Learn python from scratch] 10. Detailed explanation of Python conditional statements and if nesting
[Learn python from scratch] 09. Conditional judgment statements in Python
[Learn python from scratch] 08. Python understands bit operations operator, operator priority
[Learn python from scratch] 07. Detailed explanation of Python operators: assignment, comparison and logical operators
[Learn python from scratch] 06. Use arithmetic operators in Python for calculations and string concatenation
[Learn from scratch] python ] 05. Output and input in Python
[Learn python from scratch] 04. Basics of Python programming: variables, data types and identifiers
[Learn python from scratch] 03. Python interactive programming and detailed explanation of comments
[Learn python from scratch] 02. Introduction to development tools
[Learn python from scratch] 01. Install and configure python